Applied Nano

2024

Jump to: 2023, 2022, 2021, 2020

21 pages, 9027 KiB

Open AccessArticle

Tailoring Piezoresistive Performance in 3D-Printed Nanocomposite Sensors Through Cellular Geometries

by Md Ibrahim Khalil Tanim and Anahita Emami

Appl. Nano 2024, 5(4), 258-278; https://doi.org/10.3390/applnano5040017 - 26 Nov 2024

Viewed by 419

Abstract

Flexible nanocomposite sensors hold significant promise in various applications, such as wearable electronics and medical devices. This research aims to tailor the flexibility and sensitivity of 3D-printed piezoresistive nanocomposite pressure sensors through geometric design, by exploring various simple cellular structures. The geometric designs [...] Read more.

Flexible nanocomposite sensors hold significant promise in various applications, such as wearable electronics and medical devices. This research aims to tailor the flexibility and sensitivity of 3D-printed piezoresistive nanocomposite pressure sensors through geometric design, by exploring various simple cellular structures. The geometric designs were specifically selected to be 3D printable with a flexible material, allowing evaluation of the impact of different structures on sensor performance. In this study, we used both experimental and finite element (FE) methods to investigate the effect of geometric design on piezoresistive sensors. We fabricated the sensors using a flexible resin mixed with conductive nanoparticles via a Stereolithography (SLA) additive manufacturing technique. Electromechanical testing was carried out to evaluate the performance of four different sensor designs. Finite element (FE) models were developed, and their results were compared with experimental data to validate the simulations. The results demonstrated that auxetic structure exhibited the highest sensitivity and lowest stiffness both in experimental and FE analysis, highlighting its potential for applications requiring highly responsive materials. The validated FE model was further used for a parametric study of one of the promising simple designs, revealing that variations in geometric parameters significantly impact piezoresistive sensitivity. These findings provide valuable insights for advancing the development of pressure sensors with tailored sensitivity characteristics. Full article

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18 pages, 2434 KiB

Open AccessArticle

Amine-Terminated Silver Nanoparticles Exhibit Potential for Selective Targeting of Triple-Negative Breast Cancer

by Jayshree H. Ahire, Qi Wang, Yuewei Tao, Yimin Chao and Yongping Bao

Appl. Nano 2024, 5(4), 227-244; https://doi.org/10.3390/applnano5040015 - 18 Oct 2024

Viewed by 1101

Abstract

Silver nanoparticles (AgNPs) demonstrate potential in treating aggressive cancers such as triple-negative breast cancer (TNBC) in preclinical models. To further the development of AgNP-based therapeutics for clinical use, it is essential to clearly define the specific physicochemical characteristics of the nanoparticles and connect [...] Read more.

Silver nanoparticles (AgNPs) demonstrate potential in treating aggressive cancers such as triple-negative breast cancer (TNBC) in preclinical models. To further the development of AgNP-based therapeutics for clinical use, it is essential to clearly define the specific physicochemical characteristics of the nanoparticles and connect these properties to biological outcomes. This study addresses this knowledge gap through detailed investigations into the structural and surface functional relationships, exploring the mechanisms, safety, and efficacy of AgNPs in targeting TNBC. The surface functionality of nanoparticles is crucial not only for their internalization into cancer cells but also for enhancing their toxicity toward tumor cells. Although the nanoparticles internalized into cancer cells, they failed to exhibit their full toxicity against the cancer. Herein we report a solvent-assisted synthesis amine, mercaptohexanol and bifunctional silver nanoparticles and performing comparative study to understand their selectivity and toxicity toward TNBC cells. The nanoparticles are fully characterized by UV–visible absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and dynamic light scattering measurement (DLS). The synthesis method achieves an extremely high yield and surface coating ratio of synthesized colloidal AgNPs. Our findings reveal that the amine-capped AgNPs exhibit significant selective toxicity against TNBC cell lines MCF7 and MDA-MB-231 at a concentration of 40 µg/mL without affecting normal breast cell lines MCF10A. This study underscores the potential of functionalized AgNPs in developing safe and targeted therapeutic approaches for treating aggressive cancers like TNBC, laying the groundwork for future clinical advancements. Full article

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12 pages, 7441 KiB

Open AccessFeature PaperArticle

Black TiO₂ and Oxygen Vacancies: Unraveling the Role in the Thermal Anatase-to-Rutile Transformation

by Mattia Allieta, Mauro Coduri and Alberto Naldoni

Appl. Nano 2024, 5(2), 72-83; https://doi.org/10.3390/applnano5020007 - 3 May 2024

Viewed by 1390

Abstract

Understanding the role of oxygen vacancies in the phase transformation of metal oxide nanomaterials is fundamental to design more efficient opto-electronic devices for a variety of applications, including sensing, spintronics, photocatalysis, and photo-electrochemistry. However, the structural mechanisms behind the phase transformation in reducible [...] Read more.

Understanding the role of oxygen vacancies in the phase transformation of metal oxide nanomaterials is fundamental to design more efficient opto-electronic devices for a variety of applications, including sensing, spintronics, photocatalysis, and photo-electrochemistry. However, the structural mechanisms behind the phase transformation in reducible oxides remain poorly described. Here, we compare P25 and black TiO₂ during the thermal anatase-to-rutile transformation using in situ synchrotron powder diffraction. The precise measurement of the phase fractions, unit cell parameters, and Ti-O bond sheds light on the phase transformation dynamics. Notably, we observe distinct temperature-dependent shifts in the relative phase fractions of anatase and rutile in both materials highlighting the role of the oxygen vacancy in promoting the phase transformation. We employ bond valence concepts for structural modeling, revealing unique trends in temperature evolution of Ti-O distances of black rutile, confirming that this TiO₂ phase is preferentially reduced over anatase. These findings not only enhance our understanding of phase transitions in TiO₂ but also open new ways for the design of advanced photocatalytic materials through targeted phase control. Full article

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10 pages, 1584 KiB

Open AccessCommunication

Quantum Mechanical Comparison between Lithiated and Sodiated Silicon Nanowires

by Donald C. Boone

Appl. Nano 2024, 5(2), 48-57; https://doi.org/10.3390/applnano5020005 - 1 Apr 2024

Viewed by 1040

Abstract

This computational research study will compare the specific charge capacity (SCC) between lithium ions inserted into crystallized silicon (c-Si) nanowires with that of sodium ions inserted into amorphous silicon (a-Si) nanowires. It will be demonstrated that the potential energy V(r) within a lithium–silicon [...] Read more.

This computational research study will compare the specific charge capacity (SCC) between lithium ions inserted into crystallized silicon (c-Si) nanowires with that of sodium ions inserted into amorphous silicon (a-Si) nanowires. It will be demonstrated that the potential energy V(r) within a lithium–silicon nanowire supports a coherent energy state model with discrete electron particles, while the potential energy of a sodium–silicon nanowire will be discovered to be essentially zero, and, thus, the electron current that travels through a sodiated silicon nanowire will be modeled as a free electron with wave-like characteristics. This is due to the vast differences in the electric fields of lithiated and sodiated silicon nanowires, where the electric fields are of the order of

10^{10}

V/m and

10^{- 15}

V/m, respectively. The main reason for the great disparity in electric fields is the presence of optical amplification within lithium ions and the absence of this process within sodium ions. It will be shown that optical amplification develops coherent optical interactions, which is the primary reason for the surge of specific charge capacity in the lithiated silicon nanowire. Conversely, the lack of optical amplification is the reason for the incoherent optical interactions within sodium ions, which is the reason for the low presence of SCC in sodiated silicon nanowires. Full article

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13 pages, 9860 KiB

Open AccessArticle

Nano Application of Oil Concentration Detection Using Double-Tooth Ring Plasma Sensing

by Lei Li, Shubin Yan, Yang Cui, Chuanhui Zhu, Taiquan Wu, Qizhi Zhang and Guowang Gao

Appl. Nano 2024, 5(1), 20-32; https://doi.org/10.3390/applnano5010003 - 23 Feb 2024

Viewed by 1326

Abstract

Based on the unique properties of optical Fano resonance and plasmonic-waveguide coupling systems, this paper explores a novel refractive index concentration sensor structure. The sensor structure is composed of a metal–insulator–metal (MIM) waveguide and two identically shaped and sized double-tooth ring couplers (DTR). [...] Read more.

Based on the unique properties of optical Fano resonance and plasmonic-waveguide coupling systems, this paper explores a novel refractive index concentration sensor structure. The sensor structure is composed of a metal–insulator–metal (MIM) waveguide and two identically shaped and sized double-tooth ring couplers (DTR). The performance structure of the nanoscale refractive index sensor with DTR cavity was comprehensively assessed using the finite element method (FEM). Due to the impact of various geometric parameters on the sensing characteristics, including the rotation angles, the widths between the double-tooth rings, and the gaps between the cavity and the waveguide, we identified an optimal novel refractive index sensor structure that boasts the best performance indices. Finally, the DTR cavity sensor achieved a sensitivity of 4137 nm/RIU and Figure of merit (FOM) of 59.1. Given the high complexity and sensitivity of the overall structure, this nanoscale refractive index sensor can be applied to the detection of oil concentration in industrial oil–water mixtures, yielding highly precise results. Full article

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2023

Jump to: 2024, 2022, 2021, 2020

14 pages, 3750 KiB

Open AccessArticle

Concurrent Thermal Reduction and Boron-Doped Graphene Oxide by Metal–Organic Chemical Vapor Deposition for Ultraviolet Sensing Application

by Beo Deul Ryu, Hyeon-Sik Jang, Kang Bok Ko, Min Han, Tran Viet Cuong, Chel-Jong Choi and Chang-Hee Hong

Appl. Nano 2024, 5(1), 1-13; https://doi.org/10.3390/applnano5010001 - 28 Dec 2023

Cited by 1 | Viewed by 1611

Abstract

We synthesized a boron-doped reduced graphene oxide (BrGO) material characterized by various electrical properties, through simultaneous thermal reduction and doping procedures, using a metal–organic chemical vapor deposition technique. X-ray photoelectron spectroscopy (XPS) was used to study the impact of the doping level on [...] Read more.

We synthesized a boron-doped reduced graphene oxide (BrGO) material characterized by various electrical properties, through simultaneous thermal reduction and doping procedures, using a metal–organic chemical vapor deposition technique. X-ray photoelectron spectroscopy (XPS) was used to study the impact of the doping level on the B bonding in the reduced graphene oxide (rGO) layer that is influenced by the annealing temperature. The synthesized BrGO layer demonstrated a high B concentration with a considerable number of O-B bonds, that were altered by annealing temperatures. This resulted in a decreased work function and the formation of a Schottky contact between the BrGO and n-type Si substrate. Due to the higher proportion of B-C and B-C₃ bonding in the BrGO/Si device than that in the rGO/Si, the decreased Schottky barrier height of the BrGO/n-Si vertical junction photodetector resulted in a higher responsivity. This study showcases a promise of a simple B-doping method in use to alter the electrical characteristics of graphene materials. Full article

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13 pages, 8151 KiB

Open AccessArticle

Magnetron Sputter Deposition of Nanostructured AlN Thin Films

by Manohar Chirumamilla, Tobias Krekeler, Deyong Wang, Peter K. Kristensen, Martin Ritter, Vladimir N. Popok and Kjeld Pedersen

Appl. Nano 2023, 4(4), 280-292; https://doi.org/10.3390/applnano4040016 - 5 Oct 2023

Cited by 4 | Viewed by 2091

Abstract

Aluminum nitride (AlN) is a material of growing interest for power electronics, fabrication of sensors, micro-electromechanical systems, and piezoelectric generators. For the latter, the formation of nanowire arrays or nanostructured films is one of the emerging research directions. In the current work, nanostructured [...] Read more.

Aluminum nitride (AlN) is a material of growing interest for power electronics, fabrication of sensors, micro-electromechanical systems, and piezoelectric generators. For the latter, the formation of nanowire arrays or nanostructured films is one of the emerging research directions. In the current work, nanostructured AlN films manufactured with normal and glancing angle magnetron sputter depositions have been investigated with scanning and transmission electron microscopy, X-ray diffraction, atomic force microscopy, and optical spectroscopy. Growth of the nanostructures was realized utilizing metal seed particles (Ag, Au, and Al), allowing the control of the nucleation and following growth of AlN. It was demonstrated how variations of seed particle material and size can be used to tune the parameters of nanostructures and morphology of the AlN films. Using normal angle deposition allowed the growth of bud-shaped structures, which consisted of pillars/lamellae with wurtzite-like crystalline structures. Deposition at a glancing angle of 85° led to a film of individual nanostructures located near each other and tilted at an angle of 33° relative to the surface normal. Such films maintained a high degree of wurtzite-like crystallinity but had a more open structure and higher roughness than the nanostructured films grown at normal incidence deposition. The developed production strategies and recipes for controlling parameters of nanostructured films pave the way for the formation of matrices to be used in piezoelectric applications. Full article

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20 pages, 9135 KiB

Open AccessArticle

Revealing the Effects of Three Different Antimicrobial Agents on E. coli Biofilms by Using Soft-Probe Scanning Electrochemical Microscopy

by Sorour Darvishi and Hubert H. Girault

Appl. Nano 2023, 4(3), 260-279; https://doi.org/10.3390/applnano4030015 - 4 Sep 2023

Cited by 1 | Viewed by 2261

Abstract

This paper evaluated the use of soft-probe scanning electrochemical microscopy complementarily with confocal laser scanning microscopy to study the effects of different antimicrobial agents and treatments on E. coli DH5α biofilm. The antimicrobial agents were sodium azide, silver nanoparticles, and a flashlight. The [...] Read more.

This paper evaluated the use of soft-probe scanning electrochemical microscopy complementarily with confocal laser scanning microscopy to study the effects of different antimicrobial agents and treatments on E. coli DH5α biofilm. The antimicrobial agents were sodium azide, silver nanoparticles, and a flashlight. The effects of these agents were monitored by measuring the change in biofilm properties, such as biofilm biomass, live/dead studies, and surface activity. The results showed that sodium azide, silver nanoparticles, and the flashlight effectively killed E. coli biofilms and explained the mode of action for each treatment. Sodium azide was more effective in killing the biofilm after a short treatment time by blocking the ATPase, while silver nanoparticles were more effective at killing the biofilm after longer treatment times through several antibiofilm actions. This work showed that scanning electrochemical microscopy (SECM) is a very valuable tool for studying the effects of antimicrobial agents on biofilms. SECM is a sensitive technique that can be used to monitor the changes in biofilm properties in real-time. Additionally, SECM does not require any sample preparation, which makes it a convenient and efficient technique. Overall, the results of this study could be used to develop new strategies for treating E. coli biofilm infections and provide valuable insights into the use of SECM to study the effects of antimicrobial agents on E. coli biofilms. Full article

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20 pages, 4444 KiB

Open AccessArticle

Fe₃O₄ Nanoparticles to Optimize the Co-Digestion of Vinasse, Filter Cake, and Deacetylation Liquor: Operational Aspects and Microbiological Routes

by Maria Paula Cardeal Volpi, Gustavo Mockaitis and Bruna de Souza Moraes

Appl. Nano 2023, 4(3), 240-259; https://doi.org/10.3390/applnano4030014 - 30 Aug 2023

Cited by 1 | Viewed by 1912

Abstract

The present work proposes the optimization of the co-digestion of vinasse, filter cake, and deacetylation liquor in a continuous reactor by adding iron(III) oxide (Fe₃O₄) nanoparticles (NPs), comparing the results with a previous reactor operation without NPs. Initially, tests [...] Read more.

The present work proposes the optimization of the co-digestion of vinasse, filter cake, and deacetylation liquor in a continuous reactor by adding iron(III) oxide (Fe₃O₄) nanoparticles (NPs), comparing the results with a previous reactor operation without NPs. Initially, tests were carried out in batches with different NP concentrations, resulting in 5 mg L⁻¹ as the best concentration to be added in the continuous reactor along the increments of the applied organic load rate (OLR). Methane (CH₄) production reached a maximum value of 2.8 ± 0.1 NLCH₄ gVS⁻¹ (normal liter methane per gram of volatile solids), and the organic matter removal reached 71 ± 0.9% in phase VI (OLR of 5.5 gVS L⁻¹ day⁻¹). This production was 90% higher than the reactor co-digestion operation without NPs. The anaerobic digestion (AD) development was stable with stable organic acid (OA) concentrations, indicating the predominance of the propionic acid route to produce CH₄. The main methanogenic Archaea identified was Methanoculleus, indicating that the predominant metabolic route was that of acetate (SAO) coupled with hydrogenotrophic methanogenesis. The use of Fe₃O₄ NPs managed to improve the AD from the first-generation and second-generation (1G2G) ethanol production residues and stimulated microbial community growth, without modifying the preferable metabolic pathways. Full article

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21 pages, 7343 KiB

Open AccessReview

Corrosion-Resisting Nanocarbon Nanocomposites for Aerospace Application: An Up-to-Date Account

by Ayesha Kausar, Ishaq Ahmad and Tingkai Zhao

Appl. Nano 2023, 4(2), 138-158; https://doi.org/10.3390/applnano4020008 - 12 May 2023

Cited by 5 | Viewed by 3056

Abstract

The design and necessity of corrosion-resisting nanocarbon nanocomposites have been investigated for cutting-edge aerospace applications. In this regard, nanocarbon nanofillers, especially carbon nanotubes, graphene, nanodiamond, etc. have been used to fill in various polymeric matrices (thermosets, thermoplastics, and conducting polymers) to develop anti-rusting [...] Read more.

The design and necessity of corrosion-resisting nanocarbon nanocomposites have been investigated for cutting-edge aerospace applications. In this regard, nanocarbon nanofillers, especially carbon nanotubes, graphene, nanodiamond, etc. have been used to fill in various polymeric matrices (thermosets, thermoplastics, and conducting polymers) to develop anti-rusting space-related nanocomposites. This review fundamentally emphases the design, anti-corrosion properties, and application of polymer/nanocarbon nanocomposites for the space sector. An electron-conducting network is created in the polymers with nanocarbon dispersion to assist in charge transportation, and thus in the polymers’ corrosion resistance features. The corrosion resistance mechanism depends upon the formation of tortuous diffusion pathways due to nanofiller arrangement in the matrices. Moreover, matrix–nanofiller interactions and interface formation play an important role in enhancing the corrosion protection properties. The anticorrosion nanocomposites were tested for their adhesion, contact angle, and impedance properties, and NaCl tests and scratch tests were carried out. Among the polymers, epoxy was found to be superior corrosion-resisting polymer, relative to the thermoplastic polymers in these nanocomposites. Among the carbon nanotubes, graphene, and nanodiamond, the carbon nanotube with a loading of up to 7 wt.% in the epoxy matrix was desirable for corrosion resistance. On the other hand, graphene contents of up to 1 wt.% and nanodiamond contents of 0.2–0.4 wt.% were desirable to enhance the corrosion resistance of the epoxy matrix. The impedance, anticorrosion, and adhesion properties of epoxy nanocomposites were found to be better than those of the thermoplastic materials. Despite the success of nanocarbon nanocomposites in aerospace applications, thorough research efforts are still needed to design high-performance anti-rusting materials to completely replace the use of metal components in the aerospace industry. Full article

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14 pages, 3080 KiB

Open AccessArticle

The Effects of Surfactant and Metal Ions on the Stability and Rheological Properties of Nanoemulsions Loaded with Gardenia Yellow Pigment

by Li Gao and Bin Li

Appl. Nano 2023, 4(2), 61-74; https://doi.org/10.3390/applnano4020005 - 4 Apr 2023

Cited by 3 | Viewed by 2231

Abstract

The present work reports the preparation of gardenia yellow pigment containing paraffin oil nanoemulsions stabilized by Span80 and Tween80. The preparation of the required nanoemulsions was optimized by testing different conditions, such as varying the hydrophilic–lipophilic balance (HLB), the emulsifier concentration [...] Read more.

The present work reports the preparation of gardenia yellow pigment containing paraffin oil nanoemulsions stabilized by Span80 and Tween80. The preparation of the required nanoemulsions was optimized by testing different conditions, such as varying the hydrophilic–lipophilic balance (HLB), the emulsifier concentration (EC), the oil–water ratio (OWR), and the temperature (T), as determined by the average droplet diameter (ADD) and polydispersity index (PDI). Our results indicated that a minimum ADD of 65.9 nm and PDI of 0.116 were obtained at an optimum HLB value of 6.0, EC of 10% (w/w), OWR of 2:1, and T of 40 °C. Both the steady-state and dynamic rheological parameters were further investigated, revealing that the emulsions exhibited pseudoplastic behaviors. The long-term stabilities of the nanoemulsions after the addition of inorganic salts were monitored by observing their visual appearances. It was found that the emulsions containing pure water or 0.1 M CaCl₂ and AlCl₃ became slightly separated, while the emulsions containing 0.1 M KCl and NaCl showed no separation after 30 days of storage at room T. This difference among different salts could be related to the number of valence electrons of their cations. The spatial electrostatic effects of the monovalent cationic (KCl and NaCl) and the nonionic surfactants were greater than the delamination/sedimentation forces of the system, which was better than the salt based on the cations with valences greater than one (CaCl₂ and AlCl₃). In conclusion, the present work illustrated the formation, rheological properties, and stability of water containing gardenia yellow pigment in paraffin oil nanoemulsions, which can be of great significance for the application of gardenia-yellow-pigment-based formulations. Full article

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16 pages, 10086 KiB

Open AccessArticle

Wild-Type and SOD1-G93A SH-SY5Y under Oxidative Stress: EVs Characterization and Topographical Distribution of Budding Vesicles

by Carolina Sbarigia, Simone Dinarelli, Francesco Mura, Luca Buccini, Francesco Vari, Daniele Passeri, Marco Rossi, Stefano Tacconi and Luciana Dini

Appl. Nano 2023, 4(1), 45-60; https://doi.org/10.3390/applnano4010004 - 15 Mar 2023

Cited by 1 | Viewed by 2255

Abstract

Extracellular vesicles (EVs) are important mediators of intercellular communication in several physiopathological conditions. Oxidative stress alters EVs release and cargo composition depending on the cell type and stimulus. Recently, most of the EVs studies have focused on the characterization of their cargo, rather [...] Read more.

Extracellular vesicles (EVs) are important mediators of intercellular communication in several physiopathological conditions. Oxidative stress alters EVs release and cargo composition depending on the cell type and stimulus. Recently, most of the EVs studies have focused on the characterization of their cargo, rather than on the morphological features (i.e., size distribution, shape, and localization on the cell surface). Due to their high heterogeneity, to fully characterize EVs both the functional and morphological characterization are required. Atomic force microscopy (AFM), introduced for cell morphological studies at the nanoscale, represents a promising method to characterize in detail EVs morphology, dynamics along the cell surface, and its variations reflecting the cell physiological status. In the present study, untreated or H₂O₂-treated wild-type and SOD1-G93A SH-SY5Y cells have been compared performing a transmission electron microscopy (TEM) and AFM morpho-quantitative analysis of budding and released vesicles. Intriguingly, our analysis revealed a differential EVs profiling, with an opposite behavior and implying different cell areas between WT and SOD1-G93A cells, on both physiological conditions and after H₂O₂ exposure. Our results empower the relationship between the morphological features and functional role, further proving the efficacy of EM/AFM in giving an overview of the cell physiology related to EVs trafficking. Full article

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7 pages, 624 KiB

Open AccessCommunication

Thin Film Deposition of MoP, a Topological Semimetal

by Robert Browning, Paul Plachinda and Raj Solanki

Appl. Nano 2023, 4(1), 38-44; https://doi.org/10.3390/applnano4010003 - 24 Feb 2023

Viewed by 2658

Abstract

MoP is a topological semimetal which has drawn attention due to its unique electrical and optical properties resulting from massless electrons. In order to utilize these properties for practical applications, it is necessary to develop a technique to produce high-quality, large-scale thin films [...] Read more.

MoP is a topological semimetal which has drawn attention due to its unique electrical and optical properties resulting from massless electrons. In order to utilize these properties for practical applications, it is necessary to develop a technique to produce high-quality, large-scale thin films of this 2D material. We report below our initial results of growth of MoP thin films using atomic layer deposition (ALD), where the film grows layer-by-layer. These films were grown on 5 cm × 5 cm silicon oxide coated Si wafers. Resistivity versus temperature measurements show that these films are metallic and includes a partial superconducting phase. The magnetoresistances of both the longitudinal and Hall currents measured at 1.8 K show a strong effect of the magnetic field on the resistivity. Density functional theory was employed to determine the lattice constants of the MoP crystal. These parameters were in good agreement with those obtained from the Rietveld fit to the XRD spectrum of the films. Full article

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13 pages, 6156 KiB

Open AccessArticle

Polyacrylonitrile-Derived Carbon Nanocoating for Long-Life High-Power Phosphate Electrodes

by Eugene E. Nazarov, Oleg A. Tyablikov, Victoria A. Nikitina, Evgeny V. Antipov and Stanislav S. Fedotov

Appl. Nano 2023, 4(1), 25-37; https://doi.org/10.3390/applnano4010002 - 1 Feb 2023

Cited by 7 | Viewed by 2855

Abstract

Carbon-coating proved an efficient and reliable strategy to increase the power capabilities and lifetime of phosphate-based positive electrode materials for Li-ion batteries. In this work, we provide a systematic study on the influence of polyacrylonitrile-(PAN)-derived carbon coating on electrochemical properties of the nanosized [...] Read more.

Carbon-coating proved an efficient and reliable strategy to increase the power capabilities and lifetime of phosphate-based positive electrode materials for Li-ion batteries. In this work, we provide a systematic study on the influence of polyacrylonitrile-(PAN)-derived carbon coating on electrochemical properties of the nanosized Li-rich Li_1+δ(Fe_0.5Mn_0.5)_1−δPO₄ (Li-rich LFMP) cathode material, as well as the characterization of carbon-coated composites by means of Raman spectroscopy for the determination of carbon graphitization degree, DF-STEM and STEM-EELS for the estimation of carbon layer thickness, uniformity and compositional homogeneity of the conductive layer respectively, and impedance spectroscopy for the determination of charge transfer resistances of the resulted composite electrodes in Li-based cells. Using PAN as a carbon coating precursor enables significantly enhancing the cycling stability of Li-rich LFMP/C compared to those conventionally obtained with the glucose precursor: up to 40% at high current loads of 5–10C retaining about 78 ± 2% of capacity after 1000 cycles. Varying the PAN-derived carbon content in the composites allows controlling the electrochemical response of the material triggering either a high-capacity or a high-power performance. Full article

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2022

Jump to: 2024, 2023, 2021, 2020

12 pages, 3241 KiB

Open AccessArticle

Complementary Photothermal Heating Effects Observed between Gold Nanorods and Conjugated Infrared-Absorbing Dye Molecules

by Kyle Culhane, Viktoriia Savchuk, Anatoliy O. Pinchuk and Kelly McNear

Appl. Nano 2022, 3(4), 233-244; https://doi.org/10.3390/applnano3040016 - 5 Dec 2022

Cited by 1 | Viewed by 2653

Abstract

Due to their biocompatibility, ease of surface modification, and heating capabilities, gold nanomaterials are considered excellent candidates for the advancement of photothermal therapy techniques and related applications in cancer treatment. Various morphologies of gold nanomaterials have been shown to heat when exposed to [...] Read more.

Due to their biocompatibility, ease of surface modification, and heating capabilities, gold nanomaterials are considered excellent candidates for the advancement of photothermal therapy techniques and related applications in cancer treatment. Various morphologies of gold nanomaterials have been shown to heat when exposed to high-powered laser irradiation, especially that which is from the near-infrared (NIR) region. While these lasers work well and are effective, light-emitting diodes (LEDs) may offer a safe and low-powered alternative to these high energy lasers. We investigated the heating capability of NIR-dye conjugated gold nanorods when exposed to an 808 nm LED light source using polyethylene glycol (PEG)-coated gold nanorods as the control. In this way, since the rods exhibited a surface plasmon resonance peak between 795 and 825 nm for both the PEG-coated rods and the dye-conjugated rods, which are fairly close to the frequency of the 530 mW, 850 nm LED light source, we were able to reveal the heating effect of the dye modification. While both morphologies heat when irradiated with the LED light, we demonstrated that the addition of an NIR dye increases the rate of heating and cooling, compared to the PEGylated counterpart. To our knowledge, the complementary effect given by the conjugated NIR-dye has not been previously reported in the literature. The targeting abilities of the NIR-dye combined with the increased heating rate of the modified particles used in this proof-of-concept work suggests that these particles may be exceptional candidates for theranostic applications. Full article

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11 pages, 3223 KiB

Open AccessFeature PaperArticle

Catalase Like-Activity of Metal NPs–Enzyme Biohybrids

by Noelia Losada-Garcia, Alba Rodriguez-Otero, Clara Ortega-Nieto, Ariane Azarmi and Jose M. Palomo

Appl. Nano 2022, 3(3), 149-159; https://doi.org/10.3390/applnano3030011 - 7 Aug 2022

Cited by 5 | Viewed by 5520

Abstract

In this work, an efficient synthesis of bionanohybrids as artificial metalloenzymes (Cu, Pd, Ag, Mn) based on the application of an enzyme as a scaffold was described. Here we evaluated the effect of changing the metal, pH of the medium, and the amount [...] Read more.

In this work, an efficient synthesis of bionanohybrids as artificial metalloenzymes (Cu, Pd, Ag, Mn) based on the application of an enzyme as a scaffold was described. Here we evaluated the effect of changing the metal, pH of the medium, and the amount of enzyme in the synthesis of these artificial metalloenzymes, where changes in the metal species and the size of the nanoparticles occur. These nanozymes were applied in the degradation of hydrogen peroxide for their evaluation as mimetics of catalase activity, the best being the Mn@CALB-H₂O, which presented MnO₂ nanostructures, with three-fold improved activity compared to Cu₂O species, CuNPs@CALB-P, and free catalase. Full article

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14 pages, 2096 KiB

Open AccessArticle

Empirical Studies on Effect of Low-Level Laser Treatment on Glioblastoma Multiforme in Combination with Ag-PMMA-PAA Nanoparticles: Paired Red Region Optical-Property Treatment Platform

by Rohini Atluri, Daniel Korir, Tae-Youl Choi and Denise Perry Simmons

Appl. Nano 2022, 3(2), 112-125; https://doi.org/10.3390/applnano3020008 - 13 Jun 2022

Cited by 1 | Viewed by 3189

Abstract

Glioblastoma multiforme is an aggressive, invasive, fatal primary heterogenic brain tumor. New treatments have not significantly improved the dismal survival rate. Low-level laser therapy reports indicate different tumor cells respond distinctly to low-level laser therapy based on laser dose (J/cm²) or [...] Read more.

Glioblastoma multiforme is an aggressive, invasive, fatal primary heterogenic brain tumor. New treatments have not significantly improved the dismal survival rate. Low-level laser therapy reports indicate different tumor cells respond distinctly to low-level laser therapy based on laser dose (J/cm²) or with nanotherapeutics. We investigated the effects of pairing two optical property-driven treatment agents—a low-level laser on glioblastoma multiforme (U251) using an He-Ne laser (632.8 nm) with 18.8 nm spherical Ag-PMMA-PAA nanoparticles, with an absorbance peak at 400 nm with a broad shoulder to 700 nm. The He-Ne treatment parameters were power (14.87 ± 0.3 mW), beam diameter (0.68 cm), and exposure time 5 min leading to a 12.28 J/cm² dose. A dose of 12.28 J/cm² was applied to Ag-PMMA-PAA nanoparticle concentrations (110–225 μM). An amount of 110 μM Ag-PMMA-PAA nanoparticles combined with an He-Ne dose at 18 h yielded 23% U251 death compared to He-Ne alone which yielded 8% U251 death. A 225 μM Ag-PMMA-PAA nanoparticle He-Ne combination resulted in an earlier, more significant, U251 death of 38% at 6 h compared to 30% with 225 μM alone at 18 h. Both treatment agents possess inherent physical and functional properties capable of redesign to enhance the observed cell death effects. Our results provide evidence supporting next-step studies to test “the redesign hypothesis” that these paired optical-driven agents provide a tunable platform that can generate significant U251 cell death increase. Full article

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10 pages, 2940 KiB

Open AccessFeature PaperArticle

Long-Term Plasmonic Stability of Copper Nanoparticles Produced by Gas-Phase Aggregation Method Followed by UV-Ozone Treatment

by Francesco Zamboni, Arūnė Makarevičiūtė and Vladimir N. Popok

Appl. Nano 2022, 3(2), 102-111; https://doi.org/10.3390/applnano3020007 - 3 May 2022

Cited by 5 | Viewed by 3153

Abstract

Coinage metal nanoparticles (NPs) are well-known for the phenomenon of localized surface plasmon resonance (LSPR), which is widely utilized for enhanced sensing and detection. LSPR stability over time is an important issue for the practical application of nanoparticle matrices. Some metals, and copper [...] Read more.

Coinage metal nanoparticles (NPs) are well-known for the phenomenon of localized surface plasmon resonance (LSPR), which is widely utilized for enhanced sensing and detection. LSPR stability over time is an important issue for the practical application of nanoparticle matrices. Some metals, and copper among those, are chemically reactive in ambient atmospheric conditions that leads to degradation of plasmonic functionality. This work reports on the formation of Cu NP matrices utilizing magnetron-sputtering gas-phase aggregation, size-selection and soft-landing on a substrate. This method provides monocrystalline NPs with high purity, thus, improving chemical inertness towards ambient gases, for example, oxygen. Additionally, a simple approach of UV-ozone treatment is shown to form an oxide shell protecting the metallic core against reactions with environmental species and stabilizing the plasmonic properties for a period of over 150 days. The suggested methodology is promising to improve the competitiveness of Cu nano-matrices with those of Au and Ag in plasmonic sensing and detection. Full article

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11 pages, 3020 KiB

Open AccessFeature PaperReview

Limits of Detection of Mycotoxins by Laminar Flow Strips: A Review

by Xinyi Zhao, Hugh J. Byrne, Christine M. O’Connor, James Curtin and Furong Tian

Appl. Nano 2022, 3(2), 91-101; https://doi.org/10.3390/applnano3020006 - 11 Apr 2022

Cited by 3 | Viewed by 3351

Abstract

Mycotoxins are secondary metabolic products of fungi. They are poisonous, carcinogenic, and mutagenic in nature and pose a serious health threat to both humans and animals, causing severe illnesses and even death. Rapid, simple and low-cost methods of detection of mycotoxins are of [...] Read more.

Mycotoxins are secondary metabolic products of fungi. They are poisonous, carcinogenic, and mutagenic in nature and pose a serious health threat to both humans and animals, causing severe illnesses and even death. Rapid, simple and low-cost methods of detection of mycotoxins are of immense importance and in great demand in the food and beverage industry, as well as in agriculture and environmental monitoring, and, for this purpose, lateral flow immunochromatographic strips (ICSTs) have been widely used in food safety and environmental monitoring. The literature to date describing the development of ICSTs for the detection of different types of mycotoxins using different nanomaterials, nanoparticle size, and replicates was reviewed in an attempt to identify the most important determinants of the limit of detection (LOD). It is found that the particle size and type of materials contribute significantly to determining the LOD. The nanoparticle sizes used in most studies have been in the range 15–45 nm and gold nanoparticle-based ICSTs have been shown to exhibit the lowest LOD. Perspectives for potential future development to reduce the LODs of ICSTs are also discussed. Full article

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11 pages, 1286 KiB

Open AccessReview

Utilization of Optical Tweezer Nanotechnology in Membrane Interaction Studies

by Arnith Eechampati and Chamaree de Silva

Appl. Nano 2022, 3(1), 43-53; https://doi.org/10.3390/applnano3010004 - 7 Feb 2022

Cited by 2 | Viewed by 4272

Abstract

Optical tweezers have been a fixture of microscopic cell manipulation since the 1990s. Arthur Ashkin’s seminal work has led to the advancement of optical tweezers as an effective tool for assay development in the fields of physics and nanotechnology. As an advanced application [...] Read more.

Optical tweezers have been a fixture of microscopic cell manipulation since the 1990s. Arthur Ashkin’s seminal work has led to the advancement of optical tweezers as an effective tool for assay development in the fields of physics and nanotechnology. As an advanced application of cell manipulation, optical tweezers have facilitated the study of a multitude of cellular and molecular interactions within the greater field of nanotechnology. In the three decades since the optical tweezers’ rise to prominence, different and versatile assays have emerged that further explore the biochemical pathways integral for cell proliferation and communication. The most critical organelle implicated in the communication and protection of single cells includes the plasma membrane. In the past three decades, novel assays have emerged which examine the plasma membrane’s role in cell-to-cell interaction and the specific protein components that serve integral membrane functions for the cell as a whole. To further understand the extent to which optical tweezers have evolved as a critical tool for cellular membrane assessment within the field of nanotechnology, the various novel assays, including pulling, indentation, and stretching assays, will be reviewed in the current research sector. Full article

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2021

Jump to: 2024, 2023, 2022, 2020

14 pages, 1939 KiB

Open AccessArticle

Characterization of Organic Molecules Grafted to Silica or Bismuth Nanoparticles by NMR

by Céline Henoumont, Gauthier Hallot, Estelle Lipani, Catherine Gomez, Robert N. Muller, Luce Vander Elst, Marc Port and Sophie Laurent

Appl. Nano 2021, 2(4), 330-343; https://doi.org/10.3390/applnano2040024 - 4 Nov 2021

Viewed by 3625

Abstract

NMR is a powerful characterization tool and we propose to study the surface of silica or bismuth nanoparticles dedicated to medical applications in order to evidence the covalent grafting of organic molecules on their surface. For that aim, DOSY experiments are particularly useful [...] Read more.

NMR is a powerful characterization tool and we propose to study the surface of silica or bismuth nanoparticles dedicated to medical applications in order to evidence the covalent grafting of organic molecules on their surface. For that aim, DOSY experiments are particularly useful and allow for the discrimination of molecules interacting strongly with the nanoparticle surface from molecules simply weakly adsorbed at the surface. We were able to characterize thoroughly the surface of different silica and bismuth nanoparticles. Full article

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16 pages, 2584 KiB

Open AccessArticle

Platinum Deposited Nitrogen-Doped Vertically Aligned Carbon Nanofibers as Methanol Tolerant Catalyst for Oxygen Reduction Reaction with Improved Durability

by Ayyappan Elangovan, Jiayi Xu, Archana Sekar, Sabari Rajendran, Bin Liu and Jun Li

Appl. Nano 2021, 2(4), 303-318; https://doi.org/10.3390/applnano2040022 - 17 Oct 2021

Cited by 4 | Viewed by 3460

Abstract

Nitrogen doping in carbon materials can modify the employed carbon material’s electronic and structural properties, which helps in creating a stronger metal-support interaction. In this study, the role of nitrogen doping in improving the durability of Pt catalysts supported on a three-dimensional vertically [...] Read more.

Nitrogen doping in carbon materials can modify the employed carbon material’s electronic and structural properties, which helps in creating a stronger metal-support interaction. In this study, the role of nitrogen doping in improving the durability of Pt catalysts supported on a three-dimensional vertically aligned carbon nanofiber (VACNF) array towards oxygen reduction reaction (ORR) was explored. The nitrogen moieties present in the N-VACNF enhanced the metal-support interaction and contributed to a reduction in the Pt particle size from 3.1 nm to 2.3 nm. The Pt/N-VACNF catalyst showed better durability when compared to Pt/VACNF and Pt/C catalysts with similar Pt loading. DFT calculations validated the increase in the durability of the Pt NPs with an increase in pyridinic N and corroborated the molecular ORR pathway for Pt/N-VACNF. Moreover, the Pt/N-VACNF catalyst was found to have excellent tolerance towards methanol crossover. Full article

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16 pages, 4363 KiB

Open AccessArticle

Mechanical Performance Enhancement of Aluminum Single-Lap Adhesive Joints Due to Organized Alumina Nanotubes Layer Formation on the Aluminum Adherends

by George C. Papanicolaou, Lykourgos C. Kontaxis, Diana V. Portan, Grigoris N. Petropoulos, Eleni Valeriou and Dimitris Alexandropoulos

Appl. Nano 2021, 2(3), 206-221; https://doi.org/10.3390/applnano2030015 - 3 Aug 2021

Cited by 7 | Viewed by 3411

Abstract

The present investigation aims to take a step forward for the transfer of a simple laboratory electrochemical method of surface nano-treatment of aluminum to industrial applications. The electrochemical method has been applied to process 1050A aluminum. Surface nano-structuring has been achieved and resulted [...] Read more.

The present investigation aims to take a step forward for the transfer of a simple laboratory electrochemical method of surface nano-treatment of aluminum to industrial applications. The electrochemical method has been applied to process 1050A aluminum. Surface nano-structuring has been achieved and resulted in the formation of an organized alumina nanotubes layer on commercial aluminum plates used as adherends for the manufacturing of aluminum single-lap adhesive joints. The mechanical properties of single-lap aluminum adhesive joints constructed with both non-anodized and anodized adherends were investigated and compared. Two types of epoxy resins were used to prove that the anodization of the adherends is equally effective, independently of the adhesives’ type. Furthermore, three overlap lengths were used (7, 10, and 25 mm) to study the effect of the overlap length on the overall joint mechanical response. Results of both three-point bending and tensile–shear testing showed that there is a considerable improvement of the joints’ mechanical performance with the addition of the nanostructures, for all the overlap lengths. It was found that the anodization method greatly contributes to the strengthening of the joints, leading to a strength increase of up to 176% and 148% for the shear and three-point bending strength, respectively. Full article

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22 pages, 2250 KiB

Open AccessFeature PaperArticle

Transfer of Cobalt Nanoparticles in a Simplified Food Web: From Algae to Zooplankton to Fish

by Nanxuan Mei, Jonas Hedberg, Mikael T. Ekvall, Egle Kelpsiene, Lars-Anders Hansson, Tommy Cedervall, Eva Blomberg and Inger Odnevall

Appl. Nano 2021, 2(3), 184-205; https://doi.org/10.3390/applnano2030014 - 22 Jul 2021

Cited by 5 | Viewed by 3990

Abstract

Cobalt (Co) nanoparticles (NPs) may be diffusely dispersed into natural ecosystems from various anthropogenic sources such as traffic settings and eventually end up in aquatic systems. As environmentally dispersed Co NPs may be transferred through an aquatic food web, this study investigated this [...] Read more.

Cobalt (Co) nanoparticles (NPs) may be diffusely dispersed into natural ecosystems from various anthropogenic sources such as traffic settings and eventually end up in aquatic systems. As environmentally dispersed Co NPs may be transferred through an aquatic food web, this study investigated this transfer from algae (Scendesmus sp.) to zooplankton (Daphnia magna) to fish (Crucian carp, Carassius carassius). Effects of interactions between naturally excreted biomolecules from D. magna and Co NPs were investigated from an environmental fate perspective. ATR-FTIR measurements showed the adsorption of both algae constituents and excreted biomolecules onto the Co NPs. Less than 5% of the Co NPs formed heteroagglomerates with algae, partly an effect of both agglomeration and settling of the Co NPs. The presence of excreted biomolecules in the solution did not affect the extent of heteroagglomeration. Despite the low extent of heteroagglomeration between Co NPs and algae, the Co NPs were transferred to the next trophic level (D. magna). The Co uptake in D. magna was 300 times larger than the control samples (without Co NP), which were not influenced by the addition of excreted biomolecules to the solution. Significant uptake of Co was observed in the intestine of the fish feeding on D. magna containing Co NPs. No bioaccumulation of Co was observed in the fish. Moreover, 10–20% of the transferred Co NP mass was dissolved after 24 h in the simulated gut solution of the zooplankton (pH 7), and 50–60% was dissolved in the simulated gut solution of the fish (pH 4). The results elucidate that Co NPs gain different properties upon trophic transfer in the food web. Risk assessments should hence be conducted on transformed and weathered NPs rather than on pristine particles. Full article

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22 pages, 1131 KiB

Open AccessFeature PaperReview

Non-Linear Thermoelectric Devices with Surface-Disordered Nanowires

by Peter Markoš and Khandker Muttalib

Appl. Nano 2021, 2(3), 162-183; https://doi.org/10.3390/applnano2030013 - 12 Jul 2021

Cited by 2 | Viewed by 3852

Abstract

We reviewed some recent ideas to improve the efficiency and power output of thermoelectric nano-devices. We focused on two essentially independent aspects: (i) increasing the charge current by taking advantage of an interplay between the material and the thermodynamic parameters, which is only [...] Read more.

We reviewed some recent ideas to improve the efficiency and power output of thermoelectric nano-devices. We focused on two essentially independent aspects: (i) increasing the charge current by taking advantage of an interplay between the material and the thermodynamic parameters, which is only available in the non-linear regime; and (ii) decreasing the heat current by using nanowires with surface disorder, which helps excite localized phonons at random positions that can strongly scatter the propagating phonons carrying the thermal current. Full article

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14 pages, 5705 KiB

Open AccessFeature PaperArticle

Hybrid ZnO/MoS₂ Core/Sheath Heterostructures for Photoelectrochemical Water Splitting

by Katerina Govatsi, Aspasia Antonelou, Labrini Sygellou, Stylianos G. Neophytides and Spyros N. Yannopoulos

Appl. Nano 2021, 2(3), 148-161; https://doi.org/10.3390/applnano2030012 - 7 Jul 2021

Cited by 6 | Viewed by 3737

Abstract

The rational synthesis of semiconducting materials with enhanced photoelectrocatalytic efficiency under visible light illumination is a long-standing issue. ZnO has been systematically explored in this field, as it offers the feasibility to grow a wide range of nanocrystal morphology; however, its wide band [...] Read more.

The rational synthesis of semiconducting materials with enhanced photoelectrocatalytic efficiency under visible light illumination is a long-standing issue. ZnO has been systematically explored in this field, as it offers the feasibility to grow a wide range of nanocrystal morphology; however, its wide band gap precludes visible light absorption. We report on a novel method for the controlled growth of semiconductor heterostructures and, in particular, core/sheath ZnO/MoS₂ nanowire arrays and the evaluation of their photoelectrochemical efficiency in oxygen evolution reaction. ZnO nanowire arrays, with a narrow distribution of nanowire diameters, were grown on FTO substrates by chemical bath deposition. Layers of Mo metal at various thicknesses were sputtered on the nanowire surface, and the Mo layers were sulfurized at low temperature, providing in a controlled way few layers of MoS₂, in the range from one to three monolayers. The heterostructures were characterized by electron microscopy (SEM, TEM) and spectroscopy (XPS, Raman, PL). The photoelectrochemical properties of the heterostructures were found to depend on the thickness of the pre-deposited Mo film, exhibiting maximum efficiency for moderate values of Mo film thickness. Long-term stability, in relation to similar heterostructures in the literature, has been observed. Full article

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20 pages, 10593 KiB

Open AccessFeature PaperArticle

Interactions and Binding Energies in Carbon Nanotube Bundles

by Thomas Rybolt and Heir Jordan

Appl. Nano 2021, 2(2), 128-147; https://doi.org/10.3390/applnano2020011 - 10 Jun 2021

Cited by 5 | Viewed by 4678

Abstract

On any size scale, it is important to know how strongly structural components are held together. The purpose of this work was to develop a means to estimate the collective binding energy holding together a bundle of aligned carbon nanotubes (CNTs). Carbon nanotubes [...] Read more.

On any size scale, it is important to know how strongly structural components are held together. The purpose of this work was to develop a means to estimate the collective binding energy holding together a bundle of aligned carbon nanotubes (CNTs). Carbon nanotubes in isolation and in bundles have unique and useful properties and applications within supramolecular structures and nanotechnology. Equations were derived to represent the total number of pairwise interactions between the CNTs found in various size and shape bundles. The shapes considered included diamond, hexagon, parallelogram, and rectangle. Parameters were used to characterize the size of a bundle for each defined shape. Force field molecular modeling was used to obtain the total bundle binding energies for a number of sample bundles. From the number of interactions per bundle, the binding energy per interaction was determined. This process was repeated for armchair CNTs having a range of length and circumference values. A simple equation described the interaction energy based on the length and circumference of the component armchair type nanotubes. When combined with the bundle shape and size parameters, the total bundle binding energy could be found. Comparison with whole bundle molecular mechanics calculations showed our formula-based approach to be effective. Full article

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20 pages, 1481 KiB

Open AccessReview

Applied Nanotechnologies in Anticoagulant Therapy: From Anticoagulants to Coagulation Test Performance of Drug Delivery Systems

by Yuri B. G. Patriota, Luíse L. Chaves, Evren H. Gocke, Patricia Severino, Mônica F. R. Soares, José L. Soares-Sobrinho and Eliana B. Souto

Appl. Nano 2021, 2(2), 98-117; https://doi.org/10.3390/applnano2020009 - 1 May 2021

Cited by 3 | Viewed by 6060

Abstract

Heparin-based delivery systems have been explored to improve their therapeutic efficacy and to reduce toxicity for different administration routes. Regardless of the applied drug delivery system (DDS), the evaluation of anticoagulant performance is instrumental for the development of a suitable DDS. The understanding [...] Read more.

Heparin-based delivery systems have been explored to improve their therapeutic efficacy and to reduce toxicity for different administration routes. Regardless of the applied drug delivery system (DDS), the evaluation of anticoagulant performance is instrumental for the development of a suitable DDS. The understanding of the range of anticoagulant assays, together with their key applications and limitations, is essential both within the context of scientific research and for clinical usage. This review provides an overview of the current anticoagulant therapy and discusses the advantages and limitations of currently available anticoagulant assays. We also discuss studies involving low-molecular-weight heparin (LMWH)-based nanocarriers with emphasis on their anticoagulation performance. Conventional anticoagulants have been used for decades for the treatment of many diseases. Direct oral anticoagulants have overcome some limitations of heparins and vitamin K antagonists. However, the lack of an accurate laboratory assessment, as well as the lack of a factor “xaban” (Xa) inhibitor reversal agent, remains a major problem associated with these anticoagulants. LMWHs represent anticoagulant agents with noteworthy efficacy and safety, and they have been explored to improve their outcomes with various nanocarriers through several administration routes. The main problems related to LMWHs have been surmounted, and improved efficiency may be achieved through the use of DDSs. Full article

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13 pages, 1959 KiB

Open AccessReview

Prussian Blue and Its Analogs as Novel Nanostructured Antibacterial Materials

by Angelo Taglietti, Piersandro Pallavicini and Giacomo Dacarro

Appl. Nano 2021, 2(2), 85-97; https://doi.org/10.3390/applnano2020008 - 28 Apr 2021

Cited by 4 | Viewed by 5684

Abstract

Prussian blue is an ancient artificial pigment. Its biocompatibility and the possibility of synthesizing it in nanometric size stimulated the interest of the scientific community. Many uses of Prussian blue nanoparticles have been reported in the field of nanomedicine. More recently, interest into [...] Read more.

Prussian blue is an ancient artificial pigment. Its biocompatibility and the possibility of synthesizing it in nanometric size stimulated the interest of the scientific community. Many uses of Prussian blue nanoparticles have been reported in the field of nanomedicine. More recently, interest into the potential application of Prussian blue nanoparticles as antibacterial agents has spread. Literature regarding Prussian blue and its analogs as antibacterial materials is still limited, but the number of papers has grown quickly over the last 2–3 years. Full article

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15 pages, 2565 KiB

Open AccessArticle

Removal of Cyanotoxins–Microcystins from Water by Filtration through Granulated Composites of Bentonite with Micelles of the Cation Octadecyltrimethyl Ammonium (ODTMA)

by Assaf Sukenik, Yehudit Viner-Mozzini, Daniel Mizrahi, Imri Tamam, Ana R. Benitez and Shlomo Nir

Appl. Nano 2021, 2(1), 67-81; https://doi.org/10.3390/applnano2010006 - 10 Mar 2021

Cited by 4 | Viewed by 4449

Abstract

Cyanobacteria and their toxins present potential hazards to consumers of water from lakes, reservoirs and rivers; thus, their removal via water treatment is essential. Previously, we demonstrated that nanocomposites of octadecyltrimethyl ammonium (ODTMA) complexed with clay could efficiently remove cyanobacteria and their toxins [...] Read more.

Cyanobacteria and their toxins present potential hazards to consumers of water from lakes, reservoirs and rivers; thus, their removal via water treatment is essential. Previously, we demonstrated that nanocomposites of octadecyltrimethyl ammonium (ODTMA) complexed with clay could efficiently remove cyanobacteria and their toxins from laboratory cultures and lake water. In this study, we determined the capacity of ODTMA nanocomposites to remove cyanotoxins, namely microcystins (MCs), from water to below 1 µg/L via filtration. This capacity was 1500 mg MC-LR per Kg of nanocomposite. Similar capacities were estimated for the removal of other MC congeners (MC-WR, MC-3aspWR and MC-YR), whereas substantially lower capacities were recorded for more positively charged MC congeners, such as MC-RR and MC-3aspRR. Filtration results were simulated with a filtration model, which considers convection and adsorption/desorption of one to several toxins. Model calculations for the removal of MC-LR, under a variety of situations, fitted well with all the experimentally measured values and also estimated the co-removal of several MC congeners. In agreement with model predictions, results demonstrated that in the presence of MC-WR, the emerging concentrations of MC-RR congeners eventually exceed their solution values. In conclusion, granulated nanocomposites of ODTMA–bentonite can be applied for the removal of microcystins from drinking water. Full article

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21 pages, 3511 KiB

Open AccessArticle

RF Sputter-Deposited Nanostructured CuO Films for Micro-Supercapacitors

by Goddati Mahendra, Reddappagari Malathi, Sairam P. Kedhareswara, Ambadi Lakshmi-Narayana, Merum Dhananjaya, Nunna Guruprakash, Obili M. Hussain, Alain Mauger and Christian M. Julien

Appl. Nano 2021, 2(1), 46-66; https://doi.org/10.3390/applnano2010005 - 25 Feb 2021

Cited by 22 | Viewed by 5577

Abstract

Copper oxide is considered as an alternative electrode material for supercapacitors due to its low cost, chemical stability and high theoretical specific capacitance. In the present work, nanostructured copper oxide (CuO) films are prepared by radio-frequency (RF) magnetron sputtering, and the influence of [...] Read more.

Copper oxide is considered as an alternative electrode material for supercapacitors due to its low cost, chemical stability and high theoretical specific capacitance. In the present work, nanostructured copper oxide (CuO) films are prepared by radio-frequency (RF) magnetron sputtering, and the influence of the substrate temperature on the microstructure and supercapacitive properties was studied. The copper oxide films prepared at 350 °C exhibit a predominant (

\bar{1}

11) orientation corresponding to the monoclinic Cu(II)O phase with a crystallite size of 24 nm. The surface of the film consists of uniformly distributed oval-like grains providing a high surface roughness of 45 nm. The films exhibit an optical bandgap of 1.68 ± 0.01 eV and an electrical conductivity of 0.4 S cm⁻¹ at room temperature. The as-prepared CuO films deliver a discharge specific capacitance of 387 mF cm⁻² (375 F g⁻¹) at a current density of 1 mA cm⁻² with excellent cyclic capacitance retention of 95% (367 mF cm⁻²) even after 1000 cycles. Hence, these films are potential electrodes for micro-supercapacitors. Full article

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11 pages, 2749 KiB

Open AccessArticle

Extending the Shelf Life of Strawberries by the Sonochemical Coating of their Surface with Nanoparticles of an Edible Anti-Bacterial Compound

by Belal Abu Salha and Aharon Gedanken

Appl. Nano 2021, 2(1), 14-24; https://doi.org/10.3390/applnano2010002 - 4 Jan 2021

Cited by 20 | Viewed by 5554

Abstract

The current paper presents the coating of harvested strawberries with edible nanoparticles of Chitosan. The NPs were formed by the application of ultrasonic waves on an acidic solution of chitosan. In a one-step process the nanoparticles were created and subsequent to their formation [...] Read more.

The current paper presents the coating of harvested strawberries with edible nanoparticles of Chitosan. The NPs were formed by the application of ultrasonic waves on an acidic solution of chitosan. In a one-step process the nanoparticles were created and subsequent to their formation they were deposited on the strawberries surface. The shelf life of the NPs coated was compared with the deposition of the same amount of non-sonicated chitosan, i.e., coating of individual chitosan molecules on the fruit. The characterization of the coated fruits was carried out by monitoring the weight loss. TSS (total soluble solids), pH, TA (titratable acidity), and Vitamin C. Finally, the freshness of the strawberries was determined by eye observation. In addition, the characterization of the chitosan NPs was also conducted in this study by (DLS) dynamic light scattering and (SEM) scanning electron microscopy. Full article

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2020

Jump to: 2024, 2023, 2022, 2021

13 pages, 3103 KiB

Open AccessArticle

Palladium-Nanoparticles Biohybrids in Applied Chemistry

by Marco Filice, Noelia Losada-Garcia, Carlos Perez-Rizquez, Marzia Marciello, Maria del Puerto Morales and Jose M. Palomo

Appl. Nano 2021, 2(1), 1-13; https://doi.org/10.3390/applnano2010001 - 29 Dec 2020

Cited by 14 | Viewed by 4006

Abstract

Applied nanotechnology has experienced tremendous advance over the last decade. In this study, the efficient synthesis of highly stable palladium-nanoparticles (PdNPs) biohybrids based on the application of an enzyme, which induces in situ the generation of spherical nanoparticles on the protein network, has [...] Read more.

Applied nanotechnology has experienced tremendous advance over the last decade. In this study, the efficient synthesis of highly stable palladium-nanoparticles (PdNPs) biohybrids based on the application of an enzyme, which induces in situ the generation of spherical nanoparticles on the protein network, has been described. A heterogeneous material was synthesized formed with PdNPs with average sizes between 1.5 to 5 nm. These Pd nanocatalysts were successfully applied in different chemical processes: C-C bonding reactions (Suzuki and Heck reactions) and cascade processes combining enzymatic and metallic activities (hydrolysis-reduction, esterification-racemization). Full article

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